A study by the Landscape and Human Health Laboratory at the University of Illinois Urbana-Champaign found that for kids with ADHD a 20 minute walk in the park improved concentration with effect sizes (the relationship between two variables) comparable to Ritalin. The walk in the park beat out a downtown walk, and a neighborhood walk. Children also rated the park walk as significantly more fun than the other walks. Here is the abstract http://jad.sagepub.com/content/early/2008/08/25/1087054708323000.abstract.
One basis for this study is Attention Restoration Theory which was developed in environmental psychology to explain why people report feeling restored after spending time in wilderness. The theory maintains that natural environments are restorative in part because they are “gently absorbing” or hold effortless “soft-fascination”.
The researchers in the walk in the park study explain that:
…ART, which is based on work by William James, posits that attention draws on two different mechanisms: one for deliberately directed, effortful forms of attention, and another for involuntary, effortless forms of attention. The notion of two mechanisms underlying attention may partially explain why individuals with ADHD can routinely sustain focus on tasks they find interesting (i.e., tasks drawing primarily on involuntary attention) but are unable to do so for tasks they find uninteresting (i.e., tasks drawing primarily on effortful, directed attention).
In other words, ADHD is probably a result of the things you are required to do being freaking BORING… like HOMEWORK! Duh. Unfortunately rather than the blatantly obvious critique of compulsory education that I read between the lines, the authors of this study conclude that hopefully in the future nature may be used in “doses” to help us do better on homework.
In earlier work on the subject of directed attention, researcher Steven Kaplan implies there may have been historical benefit to the less directed style of attention:
It might seem peculiar that a mechanism so intimately involved with human effectiveness would be so susceptible to fatigue. Yet, in evolutionary perspective, this apparent limitation might have been quite reasonable. To be able to pay attention by choice to one particular thing for a long period of time would make one vulnerable to surprises. Being vigilant, being alert, in one’s surroundings may have been far more important than the capacity for long and intense concentration. Further, much of what was important to evolving human-wild animals, danger, caves, blood, to name a few examples-was (and still is) innately fascinating and thus does not require directed attention. It is only in the modern world that the split between the important and the interesting has become extreme. All too often the modern human must exert effort to do the important while resisting distraction from the interesting (emphasis mine). Thus the problem of fatigue of directed attention may well be of comparatively recent vintage.
If I may paraphrase, I agree with Kaplan that modern life is rather sucky. Yet, if anything many tasks of paleolithic living such as hide tanning, acorn grinding, and basketry, are incredibly slow and tedious, and would seem to require directed attention. Are they the equivalent of primitive homework? And if so, is that ability to concentrate restored by practicing more scout-like skills which require a more the ADHD style of attention!? And doesn’t “gentle absorption” or “soft-facsination” sounds a lot like being in wide-angle vision!?